The embodiments described herein relate generally to a photovoltaic (PV) power generation system, and more specifically, to methods and systems for monitoring sensors included within with the PV power generation system.
Solar energy has increasingly become an attractive source of energy and has been recognized as a clean, renewable alternative form of energy. Solar energy in the form of sunlight may be converted to electrical energy by solar cells. A more general term for devices that convert light to electrical energy is “photovoltaic cells.” Sunlight is a subset of light and solar cells are a subset of photovoltaic cells. A photovoltaic cell comprises a pair of electrodes and a light-absorbing photovoltaic material disposed therebetween. When the photovoltaic material is irradiated with light, electrons that have been confined to an atom in the photovoltaic material are released by light energy to move freely. Thus, free electrons and holes are generated. The free electrons and holes are efficiently separated so that electric energy is continuously extracted. Current commercial photovoltaic cells use a semiconductor photovoltaic material, typically silicon.
In order to obtain a higher current and voltage, solar cells are electrically connected to form a solar module. In addition to a plurality of solar cells, the solar module may also include sensors, for example, an irradiance sensor, a temperature sensor, and/or a power meter. The irradiance sensor detects a flux of radiation (e.g., solar flux) on a surface of the solar module and provides a controller with an irradiance signal proportional to the solar flux. Based on an output of the irradiance sensor, energy expected to be produced by the solar module may be calculated and/or operation of the solar module may be adjusted. For example, the configuration of the solar module may be adjusted to maximize the solar flux on the surface of the solar module. Furthermore, the output of the irradiance sensor may indicate that there is an excessive buildup of dirt on the surface of the solar module. In response, the controller may direct a cleaning device to spray the solar module with water or other appropriate solvent or to vibrate the module to remove the accumulated dirt. Faulty operation of an irradiance sensor is difficult to detect and may lead to misinterpretation of the actual power produced by the panels. Typically, a fault in an irradiance sensor is detected by conducting a root cause analysis of all components within the solar module based on historical data and log files of all the components.